1. School of Biosciences, University of Birmingham, Edgbaston, Birmingham, West Midlands, B15 2TT, U.K.
2. TU Dresden, Institut für Lebensmittel- und Bioverfahrenstechnik (Institute of Food Technology and Bioprocess Engineering) 01062 Dresden
3. Department of Biochemical Engineering, University College London, London, WC1E 6BT, U.K.
4. Department of Chemistry, University of Warwick, Coventry, Warwickshire, CV4 7AL, U.K.